I was 16 in 1958 when I noticed a sore spot at the bottom of my spine which over a period of months started to weep a clear fluid. I was diagnosed with a pilonidal cyst which was removed successfully. But after stitching the wound they sewed the dressing ( a long roll of stuff running down my crack) to my cheeks with incredibly thick thread. I still have two parallel rows of dots running down my bottom. However in contrast to many others I have never had any trouble with recurrence in 54 years.